In order to strengthen the cultivation of college students' practical ability, innovation ability and team spirit, and promote the teaching reform of higher education, the Ministry of Education held t

In order to strengthen the cultivation of college students' practical ability, innovation ability and team spirit, and promote the teaching reform of higher education, the Ministry of Education held the National Smart Car for College Students. (Ⅰ) Let "Team A and Team B are just in the top two" as event A, then P(A)= 2×3! 5! = 1 10

So what? The probability that Team A and Team B are in the top two is 1 10...(5 points).

(2) The possible values of the random variable X are 0, 1, 2, 3 (6 points).

P(X=0)= 2×4！ 5! = 2 5 ; P(X= 1)= 3×2×3！ 5! = 3 10 ; P(X=2)= 2×2！ ×3×2! 5! = 1 5 ; P(X=3)= 2×3！ 5! = 1 10

So the distribution list of x is

x 0 1 23 p253 10 1 5 1 10∴ex = 0×25+ 1×3 10+2× 1 5+3×65538。